Converting Municipal Waste into Automobile Fuel: Ethanol from NewspaperMark Mascal and Richard ScownIn this experiment, waste newspaper is pulped with acid and its cellulose hydrolyzed to produce glucose syrup that is fermented and distilled to yield ethanol. In doing so, students are introduced to carbohydrate chemistry and the use of fermentation in organic synthesis.Mascal, Mark; Scown, Richard. J. Chem. Educ.2008, 85, 546.

Acids / Bases |

Alcohols |

Applications of Chemistry |

Biotechnology |

Carbohydrates |

Qualitative Analysis |

Synthesis |

Thin Layer Chromatography

Diamagnetic Corrections and Pascal's ConstantsGordon A. Bain and John F. BerryThis article presents an explanation for the origin of diamagnetic correction factors, comprehensive tables of diamagnetic constants and their application to calculate diamagnetic susceptibility, and a simple method for estimating the correct order of magnitude for the diamagnetic correction for any given compound.Bain, Gordon A.; Berry, John F. J. Chem. Educ.2008, 85, 532.

Laboratory Computing / Interfacing |

Magnetic Properties |

Molecular Properties / Structure |

Physical Properties |

Transition Elements

A Simple Method for Drawing Chiral Mononuclear Octahedral Metal ComplexesAminou Mohamadou and Arnaud HaudrechyThis article presents a simple and progressive method to draw all of the octahedral complexes of coordination units with at least two different monodentate ligands and show their chiral properties.Mohamadou, Aminou; Haudrechy, Arnaud. J. Chem. Educ.2008, 85, 436.

Structures for the ABO(H) Blood Group: Which Textbook Is Correct?John M. RisleySix textbooks and two Internet sites show different structures for the A, B, and O(H) antigens of the ABO(H) blood group, but none of them are correct. This article emphasizes the correct molecular structures because it is important to distinguish between those carbohydrates that make up the antigens and those that are not part of the antigenic structures.Risley, John M. J. Chem. Educ.2007, 84, 1546.

A2: Element or Compound?Marilyne Stains and Vicente TalanquerParticulate questions are used to investigate the mental association between the concepts of molecule and compound in chemistry students with different levels of academic preparation. A significant proportion of students misclassify molecular elements as chemical compounds, and this association is stronger in students with higher levels of preparation.Stains, Marilyne; Talanquer, Vicente. J. Chem. Educ.2007, 84, 880.

Plastic Solar Cells: A Multidisciplinary Field To Construct Chemical Concepts from Current ResearchRafael Gómez and José L. SeguraPresents a multidisciplinary approach to the field of organic solar cells and proposes examples of this technology to illustrate core concepts in chemistry, including the photovoltaic effect, the photoinduced electron-transfer process, the correlation between physical properties and atomic electronic structures, and molecular design.Gómez, Rafael; Segura, José L. J. Chem. Educ.2007, 84, 253.

Molecular Model of trans-3-(9-Anthryl)-2-Propenoic Acid Ethyl Ester William F. ColemanThe Featured Molecules this month come from the paper by Nguyen and Weisman on solvent-free Wittig reactions and the stereochemical consequences of crowding in the transition state. The molecules include those pictured in the paper as well as the cis isomer of 3-(9-anthryl)-2-propenoic acid ethyl ester.Coleman, William F. J. Chem. Educ.2007, 84, 121.

A Developmental History of Polymer Mass SpectrometryMatthew J. Vergne, Robert P. Lattimer, and David M. HerculesThis review provides a historical perspective of the development of polymer mass spectrometry, divided into three eras: the small molecule era (1950s and 1960s); the macromass era (1970s and 1980s); and the modern era (the late 1980s to the present).Vergne, Matthew J.; Lattimer, Robert P.; Hercules, David M. J. Chem. Educ.2007, 84, 81.

A Discovery-Learning 2,4-Dinitrophenylhydrazone ExperimentBruno M. Vittimberga and Ben RuekbergSelections of liquid aldehydes and ketones are proposed for students to determine what property is the best predictor of the color (yellow to red) of their 2,4-dinitrophenylhydrazone derivative. Students may use a computer (spreadsheet or word processor) to analyze their results.Vittimberga, Bruno M.; Ruekberg, Ben. J. Chem. Educ.2006, 83, 1661.

Aldehydes / Ketones |

Molecular Properties / Structure |

Physical Properties |

Qualitative Analysis

Molecular Model of Creatine SynthesisWilliam F. ColemanThe Featured Molecules for this month come from the synthesis of creatine and illustrate some of the limitations associated with the computation of molecular structure. Coleman, William F. J. Chem. Educ.2006, 83, 1657.

Molecular Modeling |

Molecular Properties / Structure |

Bioorganic Chemistry

Astrochemistry Examples in the ClassroomReggie L. HudsonIn this article some recent developments in astrochemistry are suggested as examples for the teaching of acid-base chemistry, molecular structure, and chemical reactivity. Suggestions for additional reading are provided, with an emphasis on readily-accessible materials.Hudson, Reggie L. J. Chem. Educ.2006, 83, 1611.

The Chemistry of Popcorn: Polymers of GlucoseWilliam F. ColemanThe Featured Molecules this month are all polymers of glucose and include cellobiose, maltose, 10-mer of cellulose, 40-mer of amylose, and an amylopectin fragment.Coleman, William F. J. Chem. Educ.2006, 83, 413.

Synthesis of Methyl Diantilis, a Commercially Important FragranceWilliam H. Miles and Katelyn B. ConnellDescribes the synthesis of a family of fragrances, including the commercially important Methyl Diantilis, and provides an excellent introduction to intellectual property laws. Miles, William H.; Connell, Katelyn B. J. Chem. Educ.2006, 83, 285.

Polypyrazolylborates: ScorpionatesSwiatoslaw TrofimenkoKey features of polypyrazolylborates (also known as scorpionates because of certain specific features of their coordination chemistry) and examples of their use in modeling biologically active compounds are briefly presented.Trofimenko, Swiatoslaw. J. Chem. Educ.2005, 82, 1715.

Coordination Compounds |

Heterocycles |

Synthesis |

Bioinorganic Chemistry |

Molecular Properties / Structure

Cotton Effect in Copper–Proline Complexes in the Visible RegionVictor Volkov and Rolf PfisterThis article suggests taking advantage of the visible dd electronic transition of Cu2+, which allows one to contrast the normal optical rotatory dispersion response of d- and l-proline in aqueous solution with the strong Cotton effect observed when these amino acids are complexed with a metal cation.Volkov, Victor; Pfister, Rolf. J. Chem. Educ.2005, 82, 1663.

Chirality / Optical Activity |

IR Spectroscopy |

Molecular Properties / Structure |

Spectroscopy |

Stereochemistry |

UV-Vis Spectroscopy |

Amino Acids |

Coordination Compounds |

Crystal Field / Ligand Field Theory

Nicotine Smoke ChemistryWilliam F. ColemanAs educators we must constantly make decisions about how one introduces students to both the principles of chemistry and the complexity of real chemical systems. The Featured Molecules this month come from the paper by Jeffrey Seeman detailing some of the complexities involved in the volatilization of two alkaloids, nicotine and cocaine. Students could be asked to identify how chemistry is involved in the various steps described in the paper, and most beginning students will be surprised to learn just how complex a process the volatilization of a molecule such as nicotine is.Coleman, William F. J. Chem. Educ.2005, 82, 1583.

Molecular Modeling |

Molecular Properties / Structure

Application of ChemDraw NMR Tool: Correlation of Program-Generated 13C Chemical Shifts and pKa Values of para-Substituted Benzoic AcidsHongyi WangAn application of ChemDraw NMR Tool was demonstrated by correlation of program-generated 13C NMR chemical shifts and pKa values of para-substituted benzoic acids. Experimental 13C NMR chemical shifts were analyzed in the same way for comparison. The project can be used as an assignment at the end of the first-year organic chemistry course to review topics or explore new techniques: Hammett equation, acidbase equilibrium theory, electronic nature of functional groups, inductive and resonance effects, structurereactivity relationship, NMR spectroscopy, literature search, database search, and ChemDraw software.Wang, Hongyi. J. Chem. Educ.2005, 82, 1340.

Acids / Bases |

Equilibrium |

NMR Spectroscopy |

Aqueous Solution Chemistry |

Carboxylic Acids

Circular Dichroism Investigation of Dess–Martin Periodinane Oxidation in the Organic Chemistry LaboratoryNicole A. Reed, Robert D. Rapp, Christian S. Hamann, and Pamela G. ArtzUsing circular dichroism, organic laboratory students investigated the change in absolute stereochemistry upon oxidation of menthol to menthone. In the first laboratory period, the oxidation was performed with DessMartin periodinane, which is a facile and less toxic oxidizing agent. Half the laboratory group performed the oxidation with ()-menthol and the other half used (+)-menthol to produce ()-menthone and (+)-menthone, respectively. The products were analyzed in the second laboratory period using infrared spectroscopy and gas chromatography/mass spectrometry to determine the fraction of starting alcohol converted to ketone. Comparison was made between CD spectra both for the menthol reactant and menthone product and for the (+)- and ()-menthone enantiomers.Reed, Nicole A.; Rapp, Robert D.; Hamann, Christian S.; Artz, Pamela G. J. Chem. Educ.2005, 82, 1053.

Instrumental Methods |

Molecular Properties / Structure |

Oxidation / Reduction |

Reactions |

Enantiomers

Menthol StereoisomersWilliam F. ColemanThe JCE Featured Molecules for July come from the paper by Edward M. Treadwell and T. Howard Black on the use of commercially available stereoisomers of menthol to illustrate properties of enantiomers and diastereomers. The paper describes the use of four of the eight possible stereoisomers. Structures of all eight stereoisomers are included in this months molecule collection, labeled by the chirality of the three chiral atoms. In addition to the exercises described in the paper, students can be asked to match the appropriate structures to those shown in the paper, or to generate structures for the isomers that are not discussed.Coleman, William F. J. Chem. Educ.2005, 82, 1048.

Use Correct ProjectionV. K. KapoorIf a substituent in a two-dimensional representation of a three dimensional molecule is to be shown as lying below the plane of the paper it should be more appropriately indicated by an inverted broken wedge. Kapoor, V. K. J. Chem. Educ.2005, 82, 838.

Enrichment / Review Materials |

Molecular Properties / Structure |

Molecular Modeling

Teaching pH Measurements with a Student-Assembled Combination Quinhydrone ElectrodeFritz Scholz, Tim Steinhardt, Heike Kahlert, Jens R. Pörksen, and Jürgen BehnertA combination pH electrode that can be assembled by the student is described. It consists of a glass holder and two sensors in the form of rubber stoppers that contain quinhydrone and graphite. The combination electrode is suitable to teach potentiometric measurements, pH measurements, and the interplay of acidbase and redox equilibria. The electrode meets highest safety standards and overcomes the troubles associated with the use of the conventional quinhydrone electrode.Scholz, Fritz; Steinhardt, Tim; Kahlert, Heike; Pörksen, Jens R.; Behnert, Jürgen. J. Chem. Educ.2005, 82, 782.

Acids / Bases |

pH |

Laboratory Equipment / Apparatus |

Electrochemistry

Electron Tunneling, a Quantum Probe for the Quantum World of NanotechnologyK. W. Hipps and L. ScudieroKey events and concepts in the development of tunneling spectroscopy, especially in the context of the scanning tunneling microscope, are reviewed. Focus is placed on the single-molecule spectroscopy of adsorbates on surfaces. Examples of molecular images with sub-molecular resolution are provided. Molecular electronic spectra obtained in the STM are displayed and contrasted with results from techniques requiring large numbers of molecules.Hipps, K. W.; Scudiero, L. J. Chem. Educ.2005, 82, 704.

Materials Science |

Molecular Properties / Structure |

Nanotechnology |

Surface Science |

Quantum Chemistry |

Electrochemistry

Physical Chemistry at the Nanometer ScaleK. W. HippsAn overview is provided of the Petroleum Research Fund sponsored summer school, "Physical Chemistry at the Nanometer Scale." Several articles resulting from the school (and printed in this issue) are introduced and placed in perspective from the standpoint of how they might be used in the undergraduate curriculum.Hipps, K. W. J. Chem. Educ.2005, 82, 693.

A Quantitative Examination of Multiple Methods for Standardizing a Dilute Hydrochloric Acid Solution in an Undergraduate Chemistry LaboratoryNancy E. Meagher, Dana B. Bowens, and B. Shawn ClarkThe objective of the project was to compare the different published methods for standardizing dilute hydrochloric acid solutions. There are three different suitable bases available for the process and multiple indicator choices. This article attempts to identify the most accurate method(s) for use in the undergraduate laboratory. Students were given an "unknown" solution of dilute HCl and assigned to standardize it by eight methods (32 titrations), reporting both their experimental results and preference for the different indicatorbase combinations.Meagher, Nancy E.; Bowens, Dana B.; Clark, B. Shawn. J. Chem. Educ.2005, 82, 428.

Acids / Bases |

Quantitative Analysis

Analysis of Natural Buffer Systems and the Impact of Acid Rain. An Environmental Project for First-Year Chemistry StudentsDavid C. Powers, Andrew T. Higgs, Matt L. Obley, Phyllis A. Leber, Kenneth R. Hess, and Claude H. YoderThe purpose of this project is to investigate the basic principles involved in acidbase buffer systems within the context of an environmental issue. It is designed for use in an introductory chemistry course. The students will learn about acidbase interactions and examine how a buffer system composed of a weak acid and its conjugate base can neutralize large quantities of strong acid while resisting drastic change in the pH of the system. Students will also analyze experimentally the various components of the most commonly occurring natural buffer system.Powers, David C.; Higgs, Andrew T.; Obley, Matt L.; Leber, Phyllis A.; Hess, Kenneth R.; Yoder, Claude H. J. Chem. Educ.2005, 82, 274.

Acids / Bases |

Aqueous Solution Chemistry |

Equilibrium

Mage: A Tool for Developing Interactive Instructional GraphicsStephen F. PavkovicThis article demonstrates some of the advantages of the Mage program: (i) construction of instructional Mage data files is straightforward and results in clear, geometrically correct images; (ii) Mage images may be viewed directly from a Java-capable Web page; (iii) several other formats may be converted to kinemages in order to use the Mage applet. This paper also discusses a related student activity. Pavkovic, Stephen F. J. Chem. Educ.2005, 82, 167.

Molecular Properties / Structure

A Set of Hands-On Exercises on Conformational AnalysisSilvina C. Pellegrinet and Ernesto G. MataThis article describes a set of comprehensive exercises on conformational analysis that employs a hands-on approach by the use of molecular modeling kits. In addition, the exercises provide illustrations of other topics such as nomenclature, functional groups, and isomerism, and introduce some notions of chirality. Pellegrinet, Silvina C.; Mata, Ernesto G. J. Chem. Educ.2005, 82, 73.

Alkanes / Cycloalkanes |

Conformational Analysis |

Constitutional Isomers |

Molecular Properties / Structure |

Stereochemistry

Analysis of Gold Ores by Fire AssayKristy M. Blyth, David N. Phillips, and Wilhelm van BronswijkThis article describes a laboratory exercise for the analysis of gold using the fire-assay technique. This method of analysis not only provides students with an introduction to the technique of fire assay, but also covers some very interesting acidbase and redox chemistry. The gold is collected in a lead button while the remainder of the constituents find their way into a slag. The gold is recovered from the lead by absorption in a boneash cupel. Blyth, Kristy M.; Phillips, David N.; van Bronswijk, Wilhelm. J. Chem. Educ.2004, 81, 1780.

Acids / Bases |

Industrial Chemistry |

Metals |

Quantitative Analysis |

Oxidation / Reduction

Cis and Trans Isomerization in Cyclic Alkenes: A Topic for Discovery Using the Results of Molecular ModelingSusan E. Barrows and Thomas H. EberleinThis article describes an activity in which students are led to discover the fundamental reasons behind the unusual instability of the trans isomers in medium-sized cycloalkenes by using the results of molecular modeling. Notably, students will make the unexpected discovery that twisting about p bonds is perhaps more facile than they had been led to believe. Barrows, Susan E.; Eberlein, Thomas H. J. Chem. Educ.2004, 81, 1529.

Covalent Bonding |

Computational Chemistry |

Molecular Modeling |

Alkenes |

Molecular Properties / Structure

Unified Approximations: A New Approach for Monoprotic Weak Acid–Base EquilibriaHarry L. Pardue, Ihab N. Odeh, and Teweldemedhin M. TesfaiThis article describes a new approach to approximate calculations for monoprotic acidbase equilibria in otherwise pure water. The new approach, identified herein as unified approximations, uses a simple decision criterion to select between situations that should be treated as deprotonation and protonation reactions. The remaining treatment takes account of changes in concentrations of conjugate acidbase pairs for all situations and ignores autoprotolysis only for situations for which the analytical concentration of either the conjugate acid or conjugate base will always be larger than zero. Pardue, Harry L.; Odeh, Ihab N.; Tesfai, Teweldemedhin M. J. Chem. Educ.2004, 81, 1367.

Acids / Bases |

Equilibrium |

Chemometrics

Exploring Organic Mechanistic Puzzles with Molecular ModelingGail Horowitz and Gary SchwartzMolecular modeling projects in the form of mechanistic organic puzzles are described. Students, working in small groups, deduced reaction mechanisms and calculated heats of formation of intermediates and products in order to predict thermodynamic and kinetic selectivities of reaction. Student performance and degree of success is discussed. Projects are appropriate for students who have completed one semester of organic chemistry. A 3 - 4 hour laboratory period is required. Horowitz, Gail; Schwartz, Gary. J. Chem. Educ.2004, 81, 1136.

Sulfuric Acid and Water: Paradoxes of DilutionI. A. LeensonThe principal goal of this article is to elucidate some uncommon phenomena that can be observed in the process of diluting sulfuric acid with water.Leenson, I. A. J. Chem. Educ.2004, 81, 991.

Boron ClustersWilliam F. ColemanThe review paper by Russell N. Grimes on boron clusters reminds us both of the past impact that these interesting structures have had on the development of our understanding of cluster chemistry and on the future development of what one might refer to as "post-fullerene" clusters.Coleman, William F. J. Chem. Educ.2004, 81, 768.

Molecular Modeling |

Molecular Properties / Structure

Lewis Acid–Base, Molecular Modeling, and Isotopic Labeling in a Sophomore Inorganic Chemistry LaboratoryChip Nataro, Michelle A. Ferguson, Katherine M. Bocage, Brian J. Hess, Vincent J. Ross, and Daniel T. SwarrComputational methods can be introduced to simulate IR spectra and to view the HOMO of the Lewis base and the LUMO of the Lewis acid. In addition to the computational exercise, NaBD4 can be used in the synthesis of the adduct in place of NaBH4. This allows the students to observe the effect of isotopic labeling on IR spectra. Nataro, Chip; Ferguson, Michelle A.; Bocage, Katherine M.; Hess, Brian J.; Ross, Vincent J.; Swarr, Daniel T. J. Chem. Educ.2004, 81, 722.

Keynotes in Organic Chemistry (Andrew F. Parsons)Joel M. KartyAs a result of the trend towards modularization of chemistry courses, the text attempts to meet the need for smaller, highly focused and accessible organic chemistry textbooks, which complement the very detailed standard texts, to guide students through the key principles of the subject.Karty, Joel M. J. Chem. Educ.2004, 81, 651.

Acids / Bases |

Equilibrium |

Mechanisms of Reactions |

Thermodynamics

The Singlet States of Molecular Oxygen Jean-Pierre Puttemans and Georges JannesAlthough the purpose of the article The Visible Spectrum of Liquid Oxygen in the General Chemistry Laboratory is an analysis of the two-moleculesone-photon absorption spectrum of oxygen, it nevertheless assigns arrangements of the electrons in an energy diagram to the two singlet states of molecular oxygen which do not seem to be correct in our opinion.Puttemans, Jean-Pierre; Jannes, Georges. J. Chem. Educ.2004, 81, 639.

Molecular Properties / Structure |

MO Theory |

UV-Vis Spectroscopy

The Singlet States of Molecular Oxygen Jean-Pierre Puttemans and Georges JannesAlthough the purpose of the article The Visible Spectrum of Liquid Oxygen in the General Chemistry Laboratory is an analysis of the two-moleculesone-photon absorption spectrum of oxygen, it nevertheless assigns arrangements of the electrons in an energy diagram to the two singlet states of molecular oxygen which do not seem to be correct in our opinion.Puttemans, Jean-Pierre; Jannes, Georges. J. Chem. Educ.2004, 81, 639.

A "Polypeptide Demonstrator"Addison AultI have used a telephone Handset Coil Cord as a simple and convenient model for the structure of a polypeptide. Ault, Addison. J. Chem. Educ.2004, 81, 196.

Proteins / Peptides |

Molecular Modeling |

Molecular Properties / Structure

An Acid Hydrocarbon: A Chemical ParadoxJeffrey T. BurkeThis article explores the use of paradox as a teaching and learning strategy. Specifically, students observe the acid-like paradoxical behavior of the hydrocarbon cyclopentadiene. This observation then serves as a springboard to an understanding of the non-benzenoid aromatics. Burke, Jeffrey T. J. Chem. Educ.2004, 81, 65.

Acids / Bases |

Aromatic Compounds

Simple Experiments To Demonstrate Proton Flux in Pseudomonas after Alkaline or Acidic StressGabriela Previtali, Walter Giordano, and Carlos E. DomenechA laboratory experiment to ascertain the bacterial response to the stress produced by suspension in different pH solutions has been developed. This laboratory experiment has the pedagogical advantage of giving chemistry students experience with the application of various pH levels to a biological system and enables the students to expand their understanding of pH to mean more than a strictly chemical concept. Previtali, Gabriela; Giordano, Walter; Domenech, Carlos E. J. Chem. Educ.2003, 80, 1468.

Acids / Bases

The pH at the First Equivalence Point in the Titration of a Diprotic AcidAddison AultI read with interest the paper entitled Easy Derivation of pH  (pKa1 + pKa2)/2 Using Autoprotolysis of HA: Doubtful Value of the Supposedly More Rigorous Equation. I believe the validity of this simple result can be seen even more easily than this paper indicates. Ault, Addison. J. Chem. Educ.2003, 80, 1382.

Acids / Bases |

Equilibrium |

pH |

Titration / Volumetric Analysis

Using Hydrocarbon Acidities To Demonstrate Principles of Organic Structure and BondingAndrew P. DicksThis article demonstrates the utility of hydrocarbon acidity as a teaching tool within the undergraduate classroom. Acidities of compounds containing only hydrogen and carbon vary by at least 50 orders of magnitude. Differences in acidities are rationalized by invoking principles of hybridization, resonance, induction, and aromaticity. Dicks, Andrew P. J. Chem. Educ.2003, 80, 1322.

E-Mail Molecules—Individualizing the Large Lecture ClassCarl C. WamserAll students in the organic chemistry class are assigned a unique set of nine molecules to report on as optional extra credit assignments. The molecules are taken from a list containing over 200 molecules on the class Web site; they represent an assortment of biologically relevant compounds, from acetaminophen to yohimbine. Wamser, Carl C. J. Chem. Educ.2003, 80, 1267.

Desymmetrization of the Tetrahedron: Stereogenic CentersPaul Lloyd-Williams and Ernest GiraltWhile the regular tetrahedron is the more straightforward model and is preferable for rationalizing stereochemistry at the undergraduate level for molecules containing stereogenic centers , it is important that both the instructor and students be fully aware that the tetrahedral model represents a simplification and that the use of irregular tetrahedra would be physically more realistic. Lloyd-Williams, Paul; Giralt, Ernest. J. Chem. Educ.2003, 80, 1178.

Teaching Introductory Organic Chemistry: 'Blooming' beyond a Simple TaxonomyMichael D. Pungente and Rodney A. BadgerApplying Bloom's taxonomy to introductory organic chemistry classes in order to help students construct their own understanding of the material rather than simply memorize it; includes examples of questions at the various cognitive levels.Pungente, Michael D.; Badger, Rodney A. J. Chem. Educ.2003, 80, 779.

Organic Spectroscopy–A Capstone ExperienceJan M. FleischerExperiment requiring students to make decisions regarding the likely structure of their sample based upon an IR spectrum before a final analysis with NMR spectroscopy.Fleischer, Jan M. J. Chem. Educ.2002, 79, 1247.

pH of Sodium Acetate SolutionsGuy SchmitzExample of buffering power in deviations of the pH of sodium acetate from calculated values.Schmitz, Guy. J. Chem. Educ.2002, 79, 29.

Acids / Bases |

Carboxylic Acids |

pH

Electron Densities, Atomic Charges, and Ionic, Covalent and Polar BondsRonald J. GillespieThe terms ionic and covalent character are vague, qualitative, and ill-defined. In contrast, the analysis of the electron density by the AIM theory leads to clearly defined quantitative properties such as the charges on the atoms and the electron density at the bond critical point that provide a sound basis for discussing bonding and geometry.Gillespie, Ronald J. J. Chem. Educ.2001, 78, 1688.

The Relative Acidities of Water and MethanolHenry I. AbrashAnalysis of the disparity between the way the acidity constant of water is presented in general chemistry and organic chemistry textbooks.Abrash, Henry I. J. Chem. Educ.2001, 78, 1496.

Lewis Structures in General Chemistry: Agreement between Electron Density Calculations and Lewis StructuresGordon H. PurserThe internuclear electron densities of a series of X-O bonds (where X = P, S, or Cl) are calculated using quantum mechanics and compared to Lewis structures for which the formal charges have been minimized; a direct relationship is found between the internuclear electron density and the bond order predicted from Lewis structures in which formal charges are minimized.Purser, Gordon H. J. Chem. Educ.2001, 78, 981.

Teaching 1H NMR Spectrometry Using Computer ModelingYoichi Habata and Sadatoshi AkaboriUse of computer modeling for teaching 1H NMR spectroscopy is described. The direction of the induced magnetic field is clarified by displaying the electrostatic potential on the molecule, when the magnetic anisotropy effect is taught. Habata, Yoichi; Akabori, Sadatoshi. J. Chem. Educ.2001, 78, 121.

Molecular Properties / Structure |

NMR Spectroscopy |

Molecular Modeling

WebSpectra: Online NMR and IR Spectra for StudentsCraig A. Merlic, Barry C. Fam, and Michael M. MillerWebSpectra is a World Wide Web site at UCLA through which organic chemistry students have convenient access to a library of problems in NMR and IR spectroscopy, ranging in difficulty from introductory to advanced. Students are presented with high-resolution spectra of unknown compounds in addition to the molecular formula. Merlic, Craig A.; Fam, Barry C.; Miller, Michael M. J. Chem. Educ.2001, 78, 118.

IR Spectroscopy |

NMR Spectroscopy |

Molecular Properties / Structure

The Strength of the Hydrohalic AcidsRoland Schmid and Arzu M. MiahThis article brings to mind that the textbook acidity constants of the hydrohalic acids (except for HF) are erroneous because of outmoded conjectures about the HX solubilities. Here we invoke theoretical calculations of HX solubilities based on current solvation models. Schmid, Roland; Miah, Arzu M. J. Chem. Educ.2001, 78, 116.

Infrared Spectroscopy in the General Chemistry LabMargaret A. HillThree laboratory exercises in which students learn to interpret infrared spectra for simple structural identification. A polymer identification lab uses familiar household polymer samples and teaches students how to use infrared spectral data to determine what bond types are present in the polymers. In a second lab, students learn to prepare potassium bromide pellets of fluorene derivatives and identify them by their functional group differences. The final exercise combines IR with several other lab techniques to identify an organic acid from a field of fourteen possibilities.Hill, Margaret A. J. Chem. Educ.2001, 78, 26.

Instrumental Methods |

IR Spectroscopy |

Molecular Properties / Structure

A Microscale Oxidation PuzzleMichael W. Pelter, Rebecca M. Macudzinski, and Mary Ellen PassarelliWe have adapted oxidation of an alcohol with sodium hypochlorite solution to a "puzzle" approach by using a diol as the substrate for oxidation. The diols under investigation have both a primary and a secondary hydroxyl group. The assignment is to perform the reaction and determine the structure of the product through interpretation of the IR spectrum. Pelter, Michael W.; Macudzinski, Rebecca M.; Passarelli, Mary Ellen. J. Chem. Educ.2000, 77, 1481.

IR Spectroscopy |

Microscale Lab |

Alcohols |

Oxidation / Reduction |

Molecular Properties / Structure

Periplanar or Coplanar?Saul Kane and William H. HershThe prefix peri, derived from the Greek for "near", was chosen to make the meaning "approximately planar". However, the current common usage of syn and antiperiplanar is planar, which is incorrect. In the interests of proper language, we suggest that future authors instead use "syn-coplanar" and "anti-coplanar".Kane, Saul; Hersh, William H. J. Chem. Educ.2000, 77, 1366.

Elucidation of Molecular Structure Using NMR Long-Range Coupling: Determination of the Single Isomer Formed in a Regiospecific ReactionSamuel Delagrange and Françoise NepveuThe experiment presented in this article introduces students to the main concepts of two essential NMR techniques for investigating molecular structure. Heteronuclear multiple bond connectivity (HMBC) and proton-coupled 13C NMR are used to determine which isomer, from a possible two, is formed by a regiospecific reaction. The demonstration, based on long-range coupling between quaternary carbons and protons on neighboring carbons, is presented step by step. Delagrange, Samuel; Nepveu, Françoise. J. Chem. Educ.2000, 77, 895.

The Story of the Wagner-Meerwein RearrangementLudmila BirladeanuThis paper tells the story of the long, arduous journey toward comprehending the mechanism of molecular rearrangements. This work involved the greatest chemists of the 19th and 20th centuries, among whom two names stand out: Georg Wagner, who showed what happens in these strange reshufflings of atoms, and Hans Meerwein, who showed how it happens. The resulting insight revolutionized the theory of organic chemistry. Birladeanu, Ludmila. J. Chem. Educ.2000, 77, 858.

SOS: A Mnemonic for the Stereochemistry of GlucoseRonald StarkeyThe mnemonic SOS (Same, Opposite, Same) can be helpful to recall the stereochemistry in either D-glucose or L-glucose. It refers to the configurations of C-2, C-3, and C-4 relative to that of C-5 in an aldohexose. Starkey, Ronald. J. Chem. Educ.2000, 77, 734.

Carbohydrates |

Stereochemistry |

Molecular Properties / Structure

Melting Point and Molecular SymmetryR. J. C. Brown and R. F. C. BrownIn 1882 Thomas Carnelley observed that high molecular symmetry is associated with high melting point. The application of the rule to a number of different molecular crystals is discussed. The rule applies to different categories of crystal for different reasons, which can be explained by thermodynamic analysis.Brown, R. J. C.; Brown, R. F. C. J. Chem. Educ.2000, 77, 724.

RasMol and Mage in the Undergraduate Biochemistry CurriculumSteven W. Weiner, Paul F. Cerpovicz, Dabney W. Dixon, Donald B. Harden, Donna S. Hobbs, and Donna L. GosnellMage and RasMol, free visualization software used to view and manipulate three-dimensional images of proteins and nucleic acids, have been incorporated extensively in the undergraduate biochemistry courses at several institutions in the University System of Georgia. Some teaching and learning activities using RasMol and Mage, and new educational resources, including the GLACTONE Web site and a CD-ROM, are described. Weiner, Steven W.; Cerpovicz, Paul F.; Dixon, Dabney W.; Harden, Donald B.; Hobbs, Donna S.; Gosnell, Donna L. J. Chem. Educ.2000, 77, 401.

Molecular Modeling |

Molecular Properties / Structure

Molecular Modeling to Predict Regioselectivity of Hydration ReactionsKate J. Graham, Kathleen Skoglund, Chris P. Schaller, William P. Muldoon, and John B. KlassenStudents oxidize several isomeric alkenes using acid-catalyzed hydration, oxymercuration/demercuration, and hydroboration to compare the regioselectivity of the different techniques. The product mixtures are subsequently analyzed by GC and IR. To explain the results fully, students use the Spartan 5.0 molecular modeling package to predict the regioselectivity of these hydration reactions. Graham, Kate J.; Skoglund, Kathleen; Schaller, Chris P.; Muldoon, William P.; Klassen, John B. J. Chem. Educ.2000, 77, 396.

Computational Chemistry |

Mechanisms of Reactions |

Reactive Intermediates |

IR Spectroscopy |

Gas Chromatography |

Molecular Recognition |

Molecular Properties / Structure |

Molecular Modeling

Multicomponent Reactions: A Convenient Undergraduate Organic Chemistry ExperimentRicardo Bossio, Stefano Marcaccini, Carlos F. Marcos, and Roberto PepinoTwo experiments for the synthesis of a -lactam and a succinimide, based on a 4-component Ugi condensation. The experimental procedures for both syntheses are identical except for the choice of the starting amine, whose electron richness is controlled by the presence or absence of an electron-withdrawing group. Bossio, Ricardo; Marcaccini, Stefano; Marcos, Carlos F.; Pepino, Roberto. J. Chem. Educ.2000, 77, 382.

Synthesis |

Drugs / Pharmaceuticals |

IR Spectroscopy |

NMR Spectroscopy |

Mechanisms of Reactions |

Molecular Properties / Structure

Thermal Denaturation of Proteins Studied by UV SpectroscopyNatasa Poklar and Gorazd VesnaverUV spectroscopy has been widely used for monitoring the unfolding of proteins. During temperature-induced denaturation the protein absorbance changes with temperature until the process of unfolding is completed. A determination of DH(Td) and DS(Td) for a-chymotrypsinogen A at pH 3.0 is demonstrated. Poklar, Natasa; Vesnaver, Gorazd. J. Chem. Educ.2000, 77, 380.

Cyclohexane: Boat Form RevisitedRonald R. SauersOrganic chemistry textbooks often cite an outdated structure for the boat conformer of cyclohexane that is based on ideal bond angles and distances. This article corrects these mistaken values.Sauers, Ronald R. J. Chem. Educ.2000, 77, 332.

Computational Chemistry |

Molecular Modeling |

Quantum Chemistry |

Molecular Properties / Structure

Quantifying Molecular CharacterP. G. NelsonWells and Jensen's classification of substances according to structure type is quantified, enabling substances having an intermediate structure to be classified precisely. Jensen's concept of the "degree of nonmolecularity" of a substance and the opposite quality, degree of molecular character, are also quantified. Nelson, Peter G. J. Chem. Educ.2000, 77, 245.

Keep Going with Cyclooctatetraene!Addison AultThis paper shows how some simple properties of cyclooctatetraene can indicate important ideas about the structure of cyclooctatetraene.Ault, Addison. J. Chem. Educ.2000, 77, 55.

Aromatic Compounds |

NMR Spectroscopy |

Mechanisms of Reactions |

Molecular Properties / Structure

Liver and Onions: DNA Extraction from Animal and Plant TissuesKaren J. Nordell, Anne-Marie L. Jackelen, S. Michael Condren, George C. Lisensky, and Arthur B. Ellis*This activity, which allows students to extract DNA from plant and animal cells, serves as a spectacular example of the complexity of biochemical structure and function and fits well with a discussion of nucleic acids, hydrogen bonding, genetic coding, and heredity. DNA extraction can also be used in conjunction with a discussion of polymers and their properties.Nordell, Karen J.; Jackelen, Anne-Marie L.; Condren, S. Michael; Lisensky, George C.; Ellis, Arthur B. J. Chem. Educ.1999, 76, 400A.

Hydrogen Bonding |

Molecular Properties / Structure |

Nucleic Acids / DNA / RNA

Identifying Softwoods and Hardwoods by Infrared SpectroscopyBrady Barker and Noel L. OwenInfrared spectra of 45 softwoods and hardwoods have been recorded. The wavenumber values of the carbonyl stretching vibration and one of the ring-breathing modes of lignin are used to distinguish softwoods from hardwoods. The differences between the absorption bands for the softwoods and hardwoods in each instance are shown to be statistically significant. Barker, Brady; Owen, Noel L. J. Chem. Educ.1999, 76, 1706.

Carbohydrates |

Instrumental Methods |

IR Spectroscopy |

Plant Chemistry |

Molecular Properties / Structure

Environmental Chemistry Using UltrasoundBelinda K. Wilmer, Edward Poziomek, and Grazyna E. OrzechowskaIn this demonstration, we describe a simple method for presenting the usefulness of sonication in environmental chemistry. When an aqueous solution of carbon tetrachloride is sonicated, it degrades to produce HCl and HOCl. These products cause a reduction of pH, which can be observed visually with a pH indicator. Wilmer, Belinda K.; Poziomek, Edward; Orzechowska, Grazyna E. J. Chem. Educ.1999, 76, 1657.

Acids / Bases |

Aqueous Solution Chemistry |

pH

Using Overhead Projector to Simulate X-ray Diffraction ExperimentsVeljko DragojlovicA demonstration to simulate X-ray diffraction experiments can be performed using an overhead projector. As a classroom activity, the spacing between the lines of a grating or, once the spacing is known, the wavelength of diffracted light can be calculated. Dragojlovic, Veljko. J. Chem. Educ.1999, 76, 1240.

The Use of Molecular Modeling and VSEPR Theory in the Undergraduate Curriculum to Predict the Three-Dimensional Structure of MoleculesBrian W. Pfennig and Richard L. FrockDespite the simplicity and elegance of the VSEPR model, however, students often have difficulty visualizing the three-dimensional shapes of molecules and learning the more subtle features of the model, such as the bond length and bond angle deviations from ideal geometry that accompany the presence of lone pair or multiple bond domains or that result from differences in the electronegativity of the bonded atoms, partial charges and molecular dipole moments, and site preferences in the trigonal bipyramidal electron geometry. Pfennig, Brian W.; Frock, Richard L. J. Chem. Educ.1999, 76, 1018.

Molecular Modeling |

Molecular Properties / Structure |

Covalent Bonding |

VSEPR Theory

A General Simulator for Acid-Base TitrationsRobert de LevieGeneral formal expressions are provided to facilitate the automatic computer calculation of acid-base titration curves of arbitrary mixtures of acids, bases, and salts, without and with activity corrections based on the Davies equation. de Levie, Robert. J. Chem. Educ.1999, 76, 987.

Acids / Bases |

Quantitative Analysis |

Titration / Volumetric Analysis

An Integrated Molecular Modeling and Melting Point Experiment for the Organic Chemistry LaboratoryThomas Poon, Sheri A. Bodolosky, and Cynthia M. NorrisAn introductory organic chemistry laboratory experiment that introduces students to the utility and caveats of computational chemistry is described. Molecular modeling software is used to determine the net dipoles and surface areas of six unknown solids. These and other noncomputational results are then correlated with data from melting point determinations of the unknowns.Poon, Thomas; Bodolosky, Sheri A.; Norris, Cynthia M. J. Chem. Educ.1999, 76, 983.

Computational Chemistry |

Noncovalent Interactions |

Molecular Properties / Structure |

Instrumental Methods

A New Method To Convert the Fischer Projection of Monosaccharide to the Haworth ProjectionQing-zhi Zhang and Shen-song ZhangThe D,L-configuration of a sugar in Haworth projection can be directly determined by designating the R,S-configuration of the highest-numbered asymmetric carbon; that is, the most distant carbon from the anomeric carbon. The R-configuration at this carbon corresponds to the D-family, and S- to the L-family. Zhang, Qing-zhi; Zhang, Shen-song. J. Chem. Educ.1999, 76, 799.

Sharpless Asymmetric Dihydroxylation: Effect of Alkene Structure on Rates and SelectivityAlan C. Spivey, R. Hanson, N. Scorah, and S. J. ThorpeEach student is assigned an alkene and performs three dihydroxylation reactions: one racemic and two enantioselective variants. The products are characterized by 1H NMR, IR, MS, [a]D20, and chiral chromatography (HPLC or GC). Comparison by the students of their results with those reported in the literature, particularly the extensive work of Sharpless, allows an exploration of the validity of Sharpless's mnemonic for predicting the stereochemical outcome of these reactions. Spivey, Alan C.; Hanson, R.; Scorah, N.; Thorpe, S. J. J. Chem. Educ.1999, 76, 655.

Synthesis |

Catalysis |

Stereochemistry |

Organometallics |

Molecular Properties / Structure

Illustrating Newman Projections by Using Overhead TransparenciesL. Phillip Silverman and John BarbaroA method of illustrating the Newman projection of a molecule using an overhead projector is described. This method, which uses two overhead transparencies linked by a thumbtack, provides both an easy and a clear way to present this type of conformational analysis to large lecture classes. Silverman, L. Phillip; Barbaro, John. J. Chem. Educ.1999, 76, 630.

Learning Theories |

Stereochemistry |

Molecular Properties / Structure

Organic Chemistry (by Joseph M. Hornback)R. Daniel LibbyThis text uses reaction mechanisms as the organizing principle, introduces structure where it is necessary to support the reactions to be studied, and considers synthesis after the mechanisms of appropriate reactions have been discussed. Libby, R. Daniel. J. Chem. Educ.1999, 76, 611.

A Way To Predict the Relative Stabilities of Structural IsomersJohn M. LyonThis paper discusses a method to evaluate the relative stabilities of structural isomers of inorganic and organic compounds. The method uses a simple set of rules that can be applied with only a knowledge of the electron configuration of the atoms and the periodic trends in atomic size.Lyon, John M. J. Chem. Educ.1999, 76, 364.

Effect of Experience on Retention and Elimination of Misconceptions about Molecular Structure and BondingJames P. Birk and Martha J. Kurtz A test designed to uncover misconceptions in molecular structure and bonding was administered to students from high school through graduate school and to some college faculty. The study tracked the disappearance of these misconceptions over a time span of 10 years of student experience, along with the development of accepted conceptions.Birk, James P.; Kurtz , Martha J. J. Chem. Educ.1999, 76, 124.

Molecular Properties / Structure |

Learning Theories

Spectroscopy of Simple MoleculesC. Baer and K. CornelyA spectroscopy experiment in which students utilize IR and NMR spectroscopy to identify the structures of three unknowns from a list of 15 carefully chosen simple organic molecules. In taking IR and NMR spectra, students learn to use state-of-the-art instrumentation that is used by practicing chemists. Baer, Carl; Cornely, Kathleen. J. Chem. Educ.1999, 76, 89.

Stereowordimers-Minding Your P's and Q'sEdward G. NeelandThe use of words having different colored sides is a excellent way to introduce stereochemical concepts that might not be easily grasped when using molecular examples. We have found that concepts such as enantiomers, diastereomers, identical molecules, chirality, achirality, mirror planes of symmetry, and internal planes of symmetry are readily understood by students when using stereowordimer examples.Neeland, Edward G. J. Chem. Educ.1998, 75, 1573.

Buffers PlusRichard W. RametteIn 1989 JCE Software published The Acid-Base Package: A Collection of Useful Programs for Proton Transfer Systems. This DOS program has been fully upgraded by the same author to the world of Windows 95. Ramette, Richard W. J. Chem. Educ.1998, 75, 1504.

Acids / Bases

Using Bad Science To Teach Good ChemistryMichael S. EpsteinThis paper presents examples of bad science ranging from "unintentional mistakes" to "fraud" that can be used as part of traditional courses in general and analytical chemistry to encourage scientific reasoning and ethical behavior, and to provide a classroom atmosphere that encourages students to think and learn. Epstein, Michael S. J. Chem. Educ.1998, 75, 1399.

A Strategy for Incorporating 13C NMR into the Organic Chemistry Lecture and Laboratory CoursesPerry C. Reeves and Chris P. ChaneyThe use of spectroscopy in establishing the structures of molecules is an important component of the first course in Organic Chemistry. However, the point in the course at which these techniques are best introduced remains uncertain. We suggest that carbon nuclear magnetic resonance spectroscopy should be introduced at an early stage of the lecture course, specifically while studying the alkanes, and used extensively for structure determination throughout the course. Reeves, Perry C.; Chaney, Chris P. J. Chem. Educ.1998, 75, 1006.

Instrumental Methods |

NMR Spectroscopy |

Fourier Transform Techniques |

Alkanes / Cycloalkanes |

Molecular Properties / Structure

Covalent and Ionic Molecules: Why Are BeF2 and AlF3 High Melting Point Solids whereas BF3 and SiF4 Are Gases?Ronald J. GillespieCalculated ionic charges show that BF3 and SiF4 are predominately ionic molecules yet in contrast to BeF2 and AlF3 they exist as gases at room temperature and form molecular solids rather than infinite three-dimensional "ionic" solids at low temperature. Whether or not ionic molecules form a three-dimensional infinite ionic lattice or a molecular solid depends more on relative atomic (ionic) sizes than on the nature of the bonding in the isolated molecule.Gillespie, Ronald J. J. Chem. Educ.1998, 75, 923.

Models and Molecules - A Workshop on StereoisomersRobert W. Baker, Adrian V. George, and Margaret M. HardingA molecular model workshop aimed at first year university undergraduates has been devised to illustrate the concepts of organic stereochemistry. The students build models to teach the relationship within, and between, conformational isomers, enantiomers, and diastereomers. Baker, Robert W.; George, Adrian V.; Harding, Margaret M. J. Chem. Educ.1998, 75, 853.

Molecular Properties / Structure |

Stereochemistry |

Molecular Modeling |

Enantiomers |

Diastereomers

NMR Spectroscopy: Processing Strategies (by Peter Bigler)Nancy S. MillsPart of a four-volume series planned to deal with all aspects of a standard NMR experiment, this text, and the accompanying exercises based on data contained on a CD-ROM, goes a long way to fill in the gaps and clarify misunderstandings about NMR processing. Mills, Nancy S. J. Chem. Educ.1998, 75, 696.

Letters to the EditorThe author points out that in a previous article, "Why Is Bismuth Subchloride Soluble in Acid," a key reaction which aids in the dissolving of bismuth subchloride is omitted.J. Chem. Educ.1998, 75, 523.

Incorporating Organic Name Reactions and Minimizing Qualitative Analysis in an Unknown Identification ExperimentClaire Castro and William KarneyThe authors have developed a new type of unknown identification experiment for the introductory organic chemistry laboratory. The unknown sample the student is provided with is the product of an organic name reaction. The student is only informed of the starting material and conditions used in the compound's synthesis, and must then: (1) deduce the compound's structure, (2) determine the name reaction and corresponding mechanism that yields the compound, and (3) present his/her results to the class. Claire Castro and William Karney. J. Chem. Educ.1998, 75, 472.

Organic Chemistry (by Maitland Jones, Jr. )Michael S. HoldenThe general framework that Jones uses is that of Lewis acids reacting with Lewis bases, with an emphasis on the interaction of filled and empty orbitals. Again and again, as you work your way through the text, there are examples of reactions being explained by the overlap of orbitals. Holden, Michael S. J. Chem. Educ.1998, 75, 291.

Portraying the Structure of MicellesF. M. Menger, R. Zana, and B. LindmanThe schematic of a micelle is given as an attempt to "disprove" the appearance of the spokes of a wheel.Menger, F. M.; Zana, R.; Lindman, B. J. Chem. Educ.1998, 75, 115.

Protecting Groups in Carbohydrate ChemistrySigthór PéturssonThe most important protecting groups in carbohydrate chemistry are reviewed. The paper is aimed at those beginning to specialize in synthetic carbohydrate chemistry and at teachers with other specialties who wish to go beyond the content of general organic chemistry textbooks.Petursson, Sigthor. J. Chem. Educ.1997, 74, 1297.

Carbohydrates |

Molecular Properties / Structure |

Synthesis

Pi-Electron Delocatlization in Organic Molecules with C-N BondsVernon G. S. Box and Hing Wan YuMolecular modeling can provide great stimulation to the pedagogical process if students and teachers use this tool to examine the structural aspects of organic molecules whose structures have been determined by X-ray crystallography. An example of this is provided by one of our undergraduate research projects that examined delocalization in p-systems.Box, Vernon G. S.; Yu, Hing Wan. J. Chem. Educ.1997, 74, 1293.

Molecular Modeling |

Molecular Properties / Structure |

Covalent Bonding |

X-ray Crystallography

Solid State Structures (Abstract of Volume 5D, Number 2)Ludwig A. MayerSolid State Structures is a collection of image files that allows the user to display, rotate, and examine individually a large collection of 3-D structure models.Mayer, Ludwig A. J. Chem. Educ.1997, 74, 1144.

Fostering Curiosity-Driven Learning through Interactive Multimedia Representations of Biological MoleculesAbby L. Parrill and Jacquelyn GervayA series of QuickTime movies have been developed and are available over the World Wide Web (WWW) to help evoke student curiosity about organic chemistry. When viewed in series the movies start with a 'big picture' view based on crystallographic data and narrow in on the basic concepts needed to understand that scientific observation.Parrill, Abby L.; Gervay, Jacquelyn. J. Chem. Educ.1997, 74, 1141.

Molecular Properties / Structure |

Molecular Modeling

Two Comments on Bond AnglesP. GlaisterThe alternative approach of using the scalar (or dot) product of vectors enables the determination of the bond angle in a tetrahedral molecule in a simple way. There is, of course, an even more straightforward derivation suitable for students who are unfamiliar with vectors, or products thereof, but who do know some elementary trigonometry.Glaister, P. J. Chem. Educ.1997, 74, 1086.

Buffer Index and Buffer Capacity for a Simple Buffer SolutionVeronica Chiriac, Gabriel BaleaMany papers that present the buffering effect of the simple buffer solution consider the notion of buffer index and buffer capacity as being equivalent. Moreover, IUPAC defies them as the same thing. According to the definition of the authors who have introduced these two units, the paper shows that there is a large difference between them.Chiriac, Veronica ; Balea, Gabriel. J. Chem. Educ.1997, 74, 937.

Hot and Spicy versus Cool and Minty as an Example of Organic Structure-Activity RelationshipsDoris R. KimbroughStructures of substances found in spices and food that we normally associate with "hot" (or spicy) and "cool" (or minty) flavors are presented and discussed. Functional group similarities within the two groups provide an interesting example of the relationship between molecular structure and molecular function. Kimbrough, Doris R. J. Chem. Educ.1997, 74, 861.

Molecules, Crystals, and ChiralityIl-Hwan Suh, Koon Ha Park, William P. Jensen, David E. Lewis*The development of the concept of chirality from the early work of Pasteur, van't Hoff and Le Bel to the work of Cahn, Ingold and Prelog is presented, and the constraints that chirality imposes on the symmetry of molecules - that chiral molecules may not possess an improper axis of rotation - is discussed. Suh, Il-Hwan; Park, Koon Ha ; Jensen, William P.; Lewis, David E. J. Chem. Educ.1997, 74, 800.

IR MENTOR PRO 2.0reviewed by John C. CochranIR Mentor Pro:2.0 appears to be the ultimate reference source for infrared spectroscopy of organic molecules. This on-line database contains more than six hundred IR band assignments arising from over two hundred functional groups. Cochran, John C. J. Chem. Educ.1997, 74, 764.

Sheldon Shore, Small Boranes, and AmmoniaRobert W. ParryThe paper discusses the early studies on "the diammoniate of diborane" and emphasizes how continuing work done by Sheldon Shore at Ohio State University extended the work on the boranes and answered here-to-fore vexing structural problems on intermediates in the borane and borane-ammonia system.Parry, Robert W. J. Chem. Educ.1997, 74, 512.

Acids / Bases |

Coordination Compounds |

Crystals / Crystallography |

Synthesis

The Chemistry of Paper Preservation: Part 4. Alkaline PaperHenry A. CarterThe use of alkaline paper can minimize the problem of acidity for new papers. This study focuses on the chemistry involved in the sizing of both acid and alkaline papers and the types of fillers used. The advantages and potential problems in alkaline paper making are also discussed. Carter, Henry A. J. Chem. Educ.1997, 74, 508.

The TCICA Test for Distinguishing Primary and Secondary AlcoholsGene A. Hiegel and Afshin K. ChaharmohalSimple primary and secondary alcohols can easily be distinguished by their rate of oxidation with trichloroisocyanuric acid (TCICA). The TCICA test is conducted by adding the unknown to a solution of TCICA in acetonitrile containing hydrochloric acid and measuring the time for a precipitate to form. Primary alcohols react slowly and secondary alcohols react rapidly.Hiegel, Gene A.; Chaharmohal, Afshin K. J. Chem. Educ.1997, 74, 423.

Alcohols |

Molecular Properties / Structure

Why is Bismuth Subchloride Soluble in Acid?Damon DiementeIt is shown that the solubility of BiOCl can be explained as a consequence of the shifting of hydrolysis equilibriums upon the addition of acid. Two demonstrations suitable for classroom use are presented, with detailed discussion of each.Diemente, Damon. J. Chem. Educ.1997, 74, 398.

Acids / Bases |

Equilibrium |

Precipitation / Solubility |

Solutions / Solvents

Discovery-Based Stereochemistry Tutorials Available on the World Wide WebAbby L. Parrill and Jacquelyn GervayThe WWW offers the ability to develop interactive, discovery-based tutorials for use as study tools, and multimedia offers significant improvements in the display of three-dimensional objects. As part of a chemical education research program, three stereochemistry tutorials were developed to capitalize on these advantages.Parrill, Abby L.; Gervay, Jacquelyn. J. Chem. Educ.1997, 74, 329.

Stereochemistry |

Molecular Properties / Structure |

Molecular Modeling

What are Isodesmic Reactions?D. A. Ponomarev and V. V. TakhistovThe heat of isodesmic (formal) reaction Q is systematically used as a measure of deviations from the additivity of bond energies. For molecules these Q values are applied to quantification of strain energies in cyclic compounds, to evaluation of aromaticity of benzene, to explanation of the reasons for deviation from additivity in the heats of formation for disubstituted benzenes and some alkenes.Ponomarev, D. A.; Takhistov, V. V. J. Chem. Educ.1997, 74, 201.

Optical Basicity: A Practical Acid-Base Theory for Oxides and OxyanionsJ. A. DuffyThe optical basicity concept relies on the Lewis approach to acids and bases and was developed for dealing with chemical problems in non-aqueous, non-protonic media such as silicates, phosphates and borates which are important in glass making and (as slags) for refining steel.Duffy, J. A. J. Chem. Educ.1996, 73, 1138.

Acids / Bases |

Lewis Acids / Bases

Four Programs for Windows: Abstract of Volume 4D, Number 2: Alkanes in MotionJae Hyun KimAlkanes in Motion depicts the molecular motion of hydrocarbons in the gas phase. Four animations from the collection are presented here. These four animations consist of two animations each of hexane and octadecane, one animation calculated to show translational motion and one to show vibrational motion. Kim, Jae Hyun. J. Chem. Educ.1996, 73, 1079.

Molecular Modeling |

Alkanes / Cycloalkanes |

Molecular Properties / Structure |

Gases

Determination of the Dissociation Constant for Monoprotic Acid by Simple pH MeasurementsR. García-Doménech, J. V. de Julián-Ortiz, G. M. Antón-Fos, and J. Galvez AlvarezThe dissociation constant for a weak monoprotic acid may be calculated in aqueous alkaline solution by straightforward pH measurements, before and after the addition of the acid, and with the advantage of not having to standardize the solutions. García-Doménech, R.; de Julián-Ortiz, J. V.; Antón-Fos, G. M.; Alvarez, J. Galvez. J. Chem. Educ.1996, 73, 792.

A Simpler Approach to "Apparent" pKa'sKildahl, NicholasAddition to a recent article on pH, indicating an approach which emphasizes the chemistry behind the titration of a weak acid.Kildahl, Nicholas J. Chem. Educ.1996, 73, 598.

All Positive Ions Give Acid Solutions in WaterStephen J. HawkesThe acidity of aqueous solutions of positive ions is never zero although many texts say incorrectly that most metals of Groups I and II and some others are not acidic.Hawkes, Stephen J. J. Chem. Educ.1996, 73, 516.

An Excel 4.0 Add-in Function to Calculate Molecular MassChristian Hauck185. In this paper, a Microsoft Excel 4.0 add-in function is presented, which consists of a parser to interpret molecular formulas and a database containing three values for the atomic masses for every element: the mass number of the most abundant isotope, the mass of the most abundant isotope, and the atomic weight. Hauck, Christian. J. Chem. Educ.1996, 73, 433.

Nomenclature / Units / Symbols |

Molecular Properties / Structure

The Teaching of Precipitation Equilibrium: A New ApproachAna M. V. S. V. CavaleiroIn this paper we present a simplified integrated approach to the calculation of the solubility in water of a salt, and the pH of the saturated solution, taking into account the acid-base reactions of the anion. Cavaleiro, Ana M. V. S. V. J. Chem. Educ.1996, 73, 423.

Precipitation / Solubility |

pH |

Solutions / Solvents |

Acids / Bases

MOLSYM: A Program on Molecular Symmetry and Group TheoryVazquez-Vidal, Luis184. Program MOLSYM provides teachers, students, and researchers with tools for dealing with diverse aspects of molecular symmetry and applying them to specific examples and problems. Vazquez-Vidal, Luis J. Chem. Educ.1996, 73, 321.

Chemistry on the WebRichard D. Mounts181. Information on obtaining, installing, and using Web browsers and Web viewers is included. Chemical MIME objects, which are 3-dimensional representations of molecular structures, are used as examples of a type of resource available on the Web that is of special interest to chemists.Mounts, Richard D. J. Chem. Educ.1996, 73, 68.

A Low-Cost Matrix Isolation Experiment: For the Undergraduate LaboratoryMark Flair and T. Rick FletcherMethod for generating and observing the reaction intermediate formed by photolysis of Cr(CO)6 in a low temperature solid matrix illustrating some of the principles of photochemistry and the relationship of spectroscopy to molecular structure.Flair, Mark; Fletcher, T. Rick. J. Chem. Educ.1995, 72, 753.

Using Models to Understand and Design SweetenersD. Eric WaltersReview of the ways in which models have been used to help us understand the relationship between chemical structure and sweet taste.Walters, D. Eric. J. Chem. Educ.1995, 72, 680.

Which Organic Molecule Should I Pick?Perkins, RobertExamples of questions requiring students to demonstrate their understanding of organic structures, nomenclature, isomerism, and chemical reactivity.Perkins, Robert J. Chem. Educ.1995, 72, 124.

Inverse Problem of Isomer EnumerationNovak, IgorHow an isomeric enumeration can be performed on a small molecule generating a vast number of possibilities from a few structural and chemical elements.Novak, Igor J. Chem. Educ.1994, 71, 512.

Representing isomeric structures: Five applications.Thall, Edwin.Five applications of a new method that the author calls Representing Isomeric Structures, in which arrows are used to point to unique sites on the carbon skeleton to represent functional groups.Thall, Edwin. J. Chem. Educ.1992, 69, 447.

An expanded Fieser model suitable for a large classroomLevinson, Alfred S.; Zupan, RudolphIn organic chemistry, one area in which models are indispensable is in introducing the conformational analysis of cyclopentane and cyclohexane rings.Levinson, Alfred S.; Zupan, Rudolph J. Chem. Educ.1992, 69, 369.

Alkanes / Cycloalkanes |

Molecular Modeling |

Molecular Properties / Structure

Solving equilibrium problems Ruekberg, BenAn equation with more than three terms is not cause for despair.Ruekberg, Ben J. Chem. Educ.1992, 69, 344.

Acidities of oxoacids: Correlation with charge distributionMeek, Terry L.In an attempt to ascertain whether acidity can be correlated with some molecular parameter, the charge distribution within 24 oxoacid molecules and their conjugate base anions were examined by calculating the partial positive or negative charge on each atom.Meek, Terry L. J. Chem. Educ.1992, 69, 270.

Symmetry elements and molecular achiralityChen, Guo-QiangThe reliability of a prediction of achirality of a molecule by inspecting a rotating plane of symmetry is ensured by following the demonstration.Chen, Guo-Qiang J. Chem. Educ.1992, 69, 159.

A simple way to draw the chair and boat conformations of cyclohexaneLeriverend, PierreUndergraduate students in chemistry and biochemistry have difficulty in representing cyclohexane according to the main conformations known as the chair and boat form. This author puts forth a suggestion to make this easier for students.Leriverend, Pierre J. Chem. Educ.1991, 68, 957.

MolVib: Visualizing molecular vibrationsHuber, DanielA software program that features animations that aid in visualizing molecular vibrations. This program can be used appropriately in several levels of chemistry.Huber, Daniel J. Chem. Educ.1991, 68, 39.

Lewis structure skills: Taxonomy and difficulty levelsBrady, Joseph A.; Milbury-Steen, John N.; Burmeister, John L.The Office of Academic Computing and Instructional Technology at the University of Delaware committed itself to developing an intelligent tutoring system for drawing Lewis dot structures. An early prototype collected considerable data about student performance, which revealed the relative difficulty of the required skills.Brady, Joseph A.; Milbury-Steen, John N.; Burmeister, John L. J. Chem. Educ.1990, 67, 491.

Molecular Properties / Structure

The Ka values of water and the hydronium ion for comparison with other acidsCampbell, Mark L.; Waite, Boyd A.A primary interest in establishing the correct Ka values for water and the hydronium ion is to be able to compare the strengths of these species acting as acids with the strengths of other compounds acting as acids.Campbell, Mark L.; Waite, Boyd A. J. Chem. Educ.1990, 67, 386.

Acids / Bases |

Water / Water Chemistry |

pH

Molecular structure and chirality (Author response)Lechner, Joseph H.When right and left hands are perceived as isolated segments of the body, possessing a mirror-image relationship, with the understanding that they cannot be superimposed, then the true sense of chirality is imparted.Lechner, Joseph H. J. Chem. Educ.1990, 67, 358.

Chirality / Optical Activity |

Molecular Properties / Structure

Molecular structure and chirality Brand, David J.The statement that a pair of hands is "chiral" was misleading and would unnecessarily frustrate students.Brand, David J. J. Chem. Educ.1990, 67, 358.

Frank C. Whitmore and steric hindrance: A duo of centennials Mosher, Harry S.; Tidwell, Thomas T.The 1888 discovery of steric hindrance by Kehrmann was followed nearly a half century later by Whitmore's paper in 1932 that used studies of the reactivities of crowded organic compounds to develop a general theory of molecular rearrangement and to establish the role of carbocations as both viable and important reaction intermediates.Mosher, Harry S.; Tidwell, Thomas T. J. Chem. Educ.1990, 67, 9.

Molecular models for the do-it-yourselferBirk, James P.; Foster, JohnInstructions for making molecular models from styrofoam balls and wooden dowels.Birk, James P.; Foster, John J. Chem. Educ.1989, 66, 1015.

The perils of carbonic acid and equilibrium constantsJencks, William P.; Altura, Rachel A.It is important to remember that the small amounts of carbon dioxide that are usually present in water can have large effects on acid-base equilibria of dilute solutions and that dilute solutions of most weak acids and bases undergo significant protonation or hydrolysis when they are dissolved in water.Jencks, William P.; Altura, Rachel A. J. Chem. Educ.1988, 65, 770.

Acids / Bases |

Equilibrium |

Aqueous Solution Chemistry

A colorful demonstration to simulate orbital hybridizationEmerson, David W.A simple, colorful demonstration involving nothing more than several beakers of colored water can speed up student comprehension of hybrid orbitals at the introductory level.Emerson, David W. J. Chem. Educ.1988, 65, 454.

Organic lecture demonstrationsSilversmith, Ernest F.Organic chemistry may not be known for its spectacular, attention getting chemical reactions. Nevertheless, this author describes a few organic chemistry reactions that put points across and generate interest. This article provides a convenient sources of demonstrations and urges others to add to the collection. Demonstrations concerning: carbohydrates, spectroscopy, proteins, amines, carbohydrates, carboxylic acids, and much more.Silversmith, Ernest F. J. Chem. Educ.1988, 65, 70.

Molecular Properties / Structure |

Nucleophilic Substitution |

Acids / Bases |

Physical Properties |

Alkenes |

Stereochemistry |

Enantiomers |

Chirality / Optical Activity |

Aldehydes / Ketones |

Alcohols

On the boiling points of the alkyl halidesCorrela, JohnMost textbooks spend some time discussing the relationship between boiling point and molecular structure, however, their reasons behind this relationship differ. This variation among textbooks warrants further investigation and discussion in order to uncover which of the factors are the major contributors to the variation of boiling point.Correla, John J. Chem. Educ.1988, 65, 62.

Molecular structure and chiralityBrand, David J.; Fisher, JedClarification of the meaning of the term chiral and its application to both chiral and achiral molecules.Brand, David J.; Fisher, Jed J. Chem. Educ.1987, 64, 1035.

How soft is mercury?Rustad, Douglas S.The conclusion that the softness of the Hg(II) ion varies going from the gas phase to different solvents is incorrect.Rustad, Douglas S. J. Chem. Educ.1987, 64, 470.

Electron spectroscopic methods in teachingAllan, MichaelPresents several spectra in a format suitable for teaching applications with the intention of promoting the use of electron energy-loss spectroscopy in teaching the electronic structure of atoms and molecules at an elementary level.Allan, Michael J. Chem. Educ.1987, 64, 418.

Synthetic design on a pocket computerPollet, Patrick73. Bits and pieces, 29. The program presented in this article is an implementation of the Hendrickson protocol for systematic synthetic design.Pollet, Patrick J. Chem. Educ.1986, 63, 624.

Relative stabilities of organic compounds using Benson's additivity rulesVitale, Dale E.The author comments that students regard organic chemistry as a subject that is a "catalog of loosely related, descriptive examples" and suggests that the relationship between structure and energy could be treated earlier and more explicitly to avoid this misconception and stress the quantitative aspect of this branch of chemistry.Vitale, Dale E. J. Chem. Educ.1986, 63, 304.

A short set of 13C-NMR correlation tablesBrown, D. W.The object of these tables is to enable a student to calculate rapidly approximate d values for 13C nuclei in as wide a variety of compounds as possible.Brown, D. W. J. Chem. Educ.1985, 62, 209.

A polymer-solution thermometer revisitedNorman, Jack C.The slight difference in the structure of two polymers leads to what appears to be a marked difference in the temperature dependencies of their solubilities. Norman, Jack C. J. Chem. Educ.1984, 61, 1094.

Models for illustrating chirality at two centersFeldman, Martin R.This note suggests common objects that can be used as models to illustrate chirality at two centers, and to introduce the concepts of diastereomers and the meso configuration.Feldman, Martin R. J. Chem. Educ.1984, 61, 1050.

Specification of R/S in a multichiral molecule (3)Aronson, John N.Any system, simple or complex, cannot be used successfully to relate the R, S designations to Fischer projections if an incorrect two-dimensional projection is made of the three-dimensional model of the structure.Aronson, John N. J. Chem. Educ.1984, 61, 90.

Molecular association and structure of hydrogen peroxideGigure, Paul A.The typical textbook treatment of molecular association and structure of hydrogen peroxide, and the implications of these concepts for the physical properties of hydrogen peroxide tend to be oversimplified and inaccurate.Gigure, Paul A. J. Chem. Educ.1983, 60, 399.

Absolute configuration in a Fischer projection: a simple approachBhushan, Ravi; Bhattacharjee, G.First year undergraduates find it hard to assign absolute configuration to a chiral center when the lowest priority group is either to the left or right of the horizontal line.Bhushan, Ravi; Bhattacharjee, G. J. Chem. Educ.1983, 60, 191.

Chirality / Optical Activity |

Molecular Properties / Structure |

Molecular Modeling

The misuse of the circle notation to represent aromatic ringsBelloli, Robert C.This chemistry educator has noticed confusion and erroneous conclusions resulting from the overuse and misuse of the circle notation to represent aromaticity in polycyclic aromatic hydrocarbons.Belloli, Robert C. J. Chem. Educ.1983, 60, 190.

A computer program for representing molecules as 3-D models Kalcher, K.37. Bits and pieces, 14. A computer program is described here that was developed to give students an adequate impression of sterical configurations by drawing molecules where spheres represent the atoms and connection lines between the bonds.Kalcher, K. J. Chem. Educ.1983, 60, 96.

Some experiments in sulfur-nitrogen chemistryBanister, Arthur J.; Smith, NigelA survey of the main structural types of sulfur-nitrogen compounds, and syntheses suitable for undergraduate experiments, that illustrate four of the five types of cyclic species.Banister, Arthur J.; Smith, Nigel J. Chem. Educ.1982, 59, 1058.

Nuclear magnetic resonance coupling constants and electronic structure in moleculesVenanzi, Thomas J.Describes the theory of NMR spin-spin coupling constants, the nature of the three types of coupling mechanisms contributing to the overall spin-spin coupling constant, and the results for two different types of coupling constants in molecules (carbon-carbon and carbon-nitrogen coupling).Venanzi, Thomas J. J. Chem. Educ.1982, 59, 144.

Structure-resonance theory for pericyclic transition statesHerndon, William C.The purpose of this article is to show that structure-resonance theory can be used to understand the effects of structure or substituents on the rates of thermal pericyclic reactions.Herndon, William C. J. Chem. Educ.1981, 58, 371.

D. I. Mendeleev's conceptions concerning the structure of complex compoundsSolov'ev, Yu. I.Mendeleev was of the first to formulate the problem of discovering similar features of various classes of compounds (ammoniates, crystalline hydrates, double salts) and to use these features as the basis for developing general conceptions about their structures.Solov'ev, Yu. I. J. Chem. Educ.1978, 55, 494.

Unified calculation of titration curvesStairs, Robert A.A method of calculation is presented that the author hopes will supplement the traditional methods based on appropriate approximations.Stairs, Robert A. J. Chem. Educ.1978, 55, 99.

Compact compactNelson, Gregory V.Using a cardboard mailing tube to demonstrate the rigidity of the folding pattern and the flexibility of a non-helical region in a protein.Nelson, Gregory V. J. Chem. Educ.1977, 54, 578.

Molecular Modeling |

Molecular Properties / Structure |

Proteins / Peptides

Synthesis in an integrated curriculumYoder, Claude H.Outline of a four-year chemistry program culminating in a senior course "Synthesis and Determination of Structure," for which a separate outline is provided.Yoder, Claude H. J. Chem. Educ.1977, 54, 572.

Purple benzene: Solubilization of anions in organic solventsHerriott, Arthur W.Demonstrates the preference of a typical salt for solution in water rather than nonpolar benzene; a quaternary ammonium salt, though soluble in water, is more soluble in benzene.Herriott, Arthur W. J. Chem. Educ.1977, 54, 229.

Chemical aspects of Bohr's 1913 theoryKragh, HelgeThe chemical content of Bohr's 1913 theory has generally been neglected in the treatises on the history of chemistry; this paper regards Bohr as a theoretical chemist and discusses the chemical aspects of his atomic theory.Kragh, Helge J. Chem. Educ.1977, 54, 208.

Periodicity / Periodic Table |

Atomic Properties / Structure |

Molecular Properties / Structure |

Covalent Bonding |

Theoretical Chemistry

CycloamylosesBergeron, Raymond J.Examines an unusual carbohydrate system of current interest in the hope of generating some enthusiasm for the topic.Bergeron, Raymond J. J. Chem. Educ.1977, 54, 204.

Vitalizing the lecture. Lap-dissolve projectionHarpp, David N.; Snyder, James P.Describes and provides examples of the lap-dissolve effect, a technique that uses two 35mm slide projectors to convey changing images in a large lecture setting.Harpp, David N.; Snyder, James P. J. Chem. Educ.1977, 54, 68.

How to see molecules in 3-D: A low cost device for stereoscopic viewsGelbard, C.Students may find some difficulties in visualizing in space the molecules drawn in their handbook. Teaching stereochemistry and reaction mechanism is made easier by the aid of stereoscopic devices such as the one described in this note.Gelbard, C. J. Chem. Educ.1976, 53, 792.

Collision and transition state theory approaches to acid-base catalysisDunford, H. B.Shows that the description of acid-catalyzed chemical reactions in terms of transition state acid dissociation constants is formally equivalent to the collision theory approach, in which dissociation constants of acid groups on initial reactants are utilized.Dunford, H. B. J. Chem. Educ.1975, 52, 578.

A simple procedure for point group classificationKrubsack, Arnold J.A flow chart that allows anyone with a basic knowledge of symmetry to deduce rapidly the specific point group of any given compound.Krubsack, Arnold J. J. Chem. Educ.1975, 52, 368.

The helix coil transition of DNASteinert, Roger; Hudson, BruceThe design and use of a photometer to detect the transition of DNA from the double helix to random coil form.Steinert, Roger; Hudson, Bruce J. Chem. Educ.1973, 50, 129.

Extraction of acid with aqueous baseSilversmith, Ernest F.This is a visual demonstration of the principle that acidic organic substances can be extracted from an organic solvent via conversion to a salt, and the latter extracted from the aqueous solution via reconversion to the acid form.Silversmith, Ernest F. J. Chem. Educ.1972, 49, A694.

Polybasic weak acids indistinguishable from monobasic ones by acid-base titrimetryMeites, LouisPresents a general equation describing the statistical ratio of the ith an (i + 1)th dissociation constants of a j-basic acid and shows that any such acid whose dissociation constants conform to those ratios will give a titration curve indistinguishable from that obtained for a monobasic acid at an appropriate concentration.Meites, Louis J. Chem. Educ.1972, 49, 682.

Perfumes and the art of perfumeryGrant, Nancy; Naves, Renee G.Examines the physical and chemical properties of perfumes, as well as several examples of compounds that constitute the essence of typical perfumes. Grant, Nancy; Naves, Renee G. J. Chem. Educ.1972, 49, 526.

Why is the oxygen in water negative?Liebman, Joel F.Oxygen in water is negative because a negative charge, unlike a positive, can be stabilized using ground state ionic resonance structures.Liebman, Joel F. J. Chem. Educ.1972, 49, 415.

Computer generated display and manipulation of a general moleculePortigal, Larry D.; Minicozzi, William P.Availability of the Molecular Display Program (MOLDSP) and algorithms written in Fortran IV that transform topological and geometrical information into dynamic molecular displays.Portigal, Larry D.; Minicozzi, William P. J. Chem. Educ.1971, 48, 790.

Dewar resonance energyBaird, N. C.In the present paper, some of the general properties of the Dewar Resonance Energy definition are developed. In particular, the DRE value for a compound is shown to be independent of the numerical values used to bond energies, and the use of DRE in judging the aromaticity of organic molecules is illustrated.Baird, N. C. J. Chem. Educ.1971, 48, 509.

Stereochemical correlations in the norbornane systemMarkgraf, J. Hodge; Leung, Pak-TongIn this experiment 2-norbornanone is converted to the epimeric 2-methyl-2-norbornanols by two routes; the structural assignments of the products are not specified, but must be determined from comparisons of various physical properties.Markgraf, J. Hodge; Leung, Pak-Tong J. Chem. Educ.1970, 47, 707.

Is ammonia like water?Gill, J. B.This article sets out to compare some of the properties of the two most widely studied solvents, water and liquid ammonia, and in particular illustrate some comparative aspects that are not normally considered.Gill, J. B. J. Chem. Educ.1970, 47, 619.

The hexaphenylethane landmark fallsSmith, William B.A reexamination of Gomberg's discovery that the treatment of triphenylmethyl chloride with silver results in hexaphenylethane has demonstrated that the dimer formed is not hexaphenylethane; a new product has been proposed.Smith, William B. J. Chem. Educ.1970, 47, 535.

A computer program for identifying organic compoundsGasser, William; Emmons, John L.This program is based on five determinations: melting or boiling point; elemental analysis for nitrogen, sulfur, and halogens; and the aluminum chloride-azoxybenzene test.Gasser, William; Emmons, John L. J. Chem. Educ.1970, 47, 137.

Computer programs for calculating pHSchlessinger, Gert G.A brief note on the availability of a Fortran II program for calculating the pH of weak acids and bases and salts of these species in aqueous solution.Schlessinger, Gert G. J. Chem. Educ.1969, 46, 680.

Wooden models of asymmetric structuresNye, Martin J.Wooden blocks are cut to represent molecules of a pair of enantiomers, and are constructed so that they may be readily stacked together to show crystal structure.Nye, Martin J. J. Chem. Educ.1969, 46, 175.

Molecular Modeling |

Molecular Properties / Structure |

Enantiomers |

Crystals / Crystallography

Monoprotic or diprotic?Goldman, James A.The author demonstrates that the results of an earlier article are not altogether unexpected.Goldman, James A. J. Chem. Educ.1969, 46, 123.

Computer simulation of experimental dataShwendeman, R. H.This note describes some of the techniques in programming used to generate a sufficient variety of experimental data to provide each student with his own set of numbers for analysis in conjunction with the demonstration laboratory.Shwendeman, R. H. J. Chem. Educ.1968, 45, 665.

Chromic acid oxidation of alcohols: A simple experiment on reaction ratesLanes, Rose M.; Lee, Donald G.In this experiment, students determine the relative rates of oxidation by adding quantities of several different alcohols to a solution of chromium(VI) in dilute sulfuric acid and visually monitoring the course of the reaction.Lanes, Rose M.; Lee, Donald G. J. Chem. Educ.1968, 45, 269.

Dissociation of weak acids and bases at infinite dilutionStock, D. IrwinIt is all too easy to forget that in a solution of infinite dilution the solvent itself is ionized to an extent governed by its ionization constant, and that the concentration of its ions will appear in the expression for the dissociation constant of the solute.Stock, D. Irwin J. Chem. Educ.1967, 44, 764.

Acids / Bases |

Aqueous Solution Chemistry |

Solutions / Solvents

Errors in representing structures of proteins and nucleic acidsDay, Richard A.; Ritter, Edmond J.It is the exceptional modern textbook in biochemistry or organic chemistry that consistently represents the structures of proteins and nucleic acids as they are found to exist in nature.Day, Richard A.; Ritter, Edmond J. J. Chem. Educ.1967, 44, 761.

Stereochemical correlations in the camphor seriesMarkgraf, J. HodgeThis paper presents a series of experiments that require the student to interpret the effect of structure on the steric course of an oxidation and a reduction in a bicyclic system.Markgraf, J. Hodge J. Chem. Educ.1967, 44, 36.

Theoretical error in acid-base titrationsButcher, John; Quintus, FernanadoThe purpose of this report is to describe simple derivations of equations for titration error calculations for a number of acid-base titrations, and to show error curves for some typical cases.Butcher, John; Quintus, Fernanado J. Chem. Educ.1966, 43, 546.

Titration / Volumetric Analysis |

Quantitative Analysis |

Acids / Bases

Improvements in the Victor-MeyerBader, MorrisTwo improvements in the Victor-Meyer have simplified the apparatus and greatly increased the accuracy of molecular weight determinations.Bader, Morris J. Chem. Educ.1966, 43, 500.

Effect of amine structure on the relative acidity of conjugate acidsGriswold, Robert E.the primary objectives of this experiment are to investigate the effect of structure of amines on the relative acidity of their conjugate acids and to study some of the factors affecting equilibrium constants.Griswold, Robert E. J. Chem. Educ.1965, 42, 483.

Acids / Bases |

Molecular Properties / Structure |

Amines / Ammonium Compounds |

Equilibrium |

pH

Applications of sodium-lead alloy in qualitative inorganic analysisEdge, Robert A.; Fowles, Gerald W. A.This note describes how sodium-lead alloy may be used n qualitative inorganic analysis, both as a reductant in acid and alkaline media, and as a source of sodium hydroxide for hydroxide precipitations.Edge, Robert A.; Fowles, Gerald W. A. J. Chem. Educ.1965, 42, 436.

Qualitative Analysis |

Acids / Bases

Extensions in the use of plastic tetrahedral modelsFieser, Louis F.Describes the modification of existing models to provide for the construction of specialized organic and inorganic structures and their use in teaching.Fieser, Louis F. J. Chem. Educ.1965, 42, 408.

Molecular Modeling |

Molecular Properties / Structure |

Alkanes / Cycloalkanes

Stereo molecular modelsGodfrey, John C.Presents a system of stereo molecular models designed by the author and their various applications.Godfrey, John C. J. Chem. Educ.1965, 42, 404.

Lineweaver-Burk treatment of acid-base dissociationSolomons, C. C.The advantage of using the Lineweaver-Burk treatment of acid-base dissociation before introducing the Henderson-Hasselbalch equation lies in the fact that K (dissociation) is determined by a straight-line relationship which is nonlogarithmic.Solomons, C. C. J. Chem. Educ.1965, 42, 225.

Teaching ionic equilibrium: Use of log chart transparenciesFreiser, Henry; Fernando, QuintusThe use of graphical methods brings the problem of significance of various terms in complicated expressions into proper focus. Furthermore, a pictorial representation permits the student to see at a glance how the concentrations of various species in a system at equilibrium change with conditions.Freiser, Henry; Fernando, Quintus J. Chem. Educ.1965, 42, 35.

The rotation of optically pure 2-bromooctaneTraynham, James C.This paper reviews the various values reported for the optical rotation of pure 2-bromooctane and makes a case for its most probable value.Traynham, James C. J. Chem. Educ.1964, 41, 617.

Models illustrating the helix-coil transition in polypeptidesHayman, H. J. G.Describes modifications of the Fisher-Hirschfelder-Taylor atom models whereby a model of a polypeptide molecule in the form of a random chain can easily be rolled up to give the alpha-helix configuration and then unrolled again to give once more a random chain.Hayman, H. J. G. J. Chem. Educ.1964, 41, 561.

Evidence for the configuration on carbon 1 of d-glucoseSickels, Jackson P.; Schultz, Harry P.The pyranose forms of alpha- and beta-D-glucose, because of the cyclohexane conformations of their six-membered rings, do not explain the results of the conductivity of these sugars in boric acid.Sickels, Jackson P.; Schultz, Harry P. J. Chem. Educ.1964, 41, 343.

Conformational analysis in the elementary organic courseAllinger, Norman L.Examines the history of conformational analysis, examples of systems in which this analysis is important, and the use of current conformational analysis research in teaching.Allinger, Norman L. J. Chem. Educ.1964, 41, 70.

The decarboxylation of organic acidMarch, JerrySimple aliphatic acids (except for acetic) do not give good yields of the corresponding alkanes through decarboxylation, although many organic chemistry textbooks cite this as a general method for the preparation of alkanes.March, Jerry J. Chem. Educ.1963, 40, 212.

Letters to the editorCockburn, B. L.Provides a mathematical treatment demonstrating the equivalence of all four C-H bonds in methane.Cockburn, B. L. J. Chem. Educ.1963, 40, 94.

Covalent Bonding |

Molecular Properties / Structure

Letters to the editorSnatzke, G.Provides a mathematical treatment demonstrating the equivalence of all four C-H bonds in methane.Snatzke, G. J. Chem. Educ.1963, 40, 94.

Covalent Bonding |

Molecular Properties / Structure

Graphical treatment simplifies acid-base equilibria calculationsThomas, E. B.In dealing with equilibria involving polybasic acids, considerable simplification of the calculation of the relative distribution of the various species with changes in pH may be obtained by a graphical treatment of the ratios involved.Thomas, E. B. J. Chem. Educ.1963, 40, 70.

LettersGoldberg, David E.The author suggests using the term "continuous chain" rather than "straight" chain so as to reduce confusion regarding the geometry of carbon chains.Goldberg, David E. J. Chem. Educ.1962, 39, 319.

Molecular Properties / Structure |

Nomenclature / Units / Symbols

LettersKoons, Lawrence F.Calls attention to a demonstration similar to that described in an earlier article.Koons, Lawrence F. J. Chem. Educ.1962, 39, 318.

Inorganic infrared spectroscopyFerraro, John R.Focuses on the use of infrared spectroscopy in solving various problems in inorganic chemistry.Ferraro, John R. J. Chem. Educ.1961, 38, 201.

Spectroscopy |

IR Spectroscopy |

Coordination Compounds |

Molecular Properties / Structure |

Organometallics |

Ionic Bonding |

Covalent Bonding

An approach to complex equilibrium problemsButler, James N.Presents an approach to equilibrium problems that sets up enough equations relating the various concentrations present to define the system completely and then makes approximations that simplify the equations.Butler, James N. J. Chem. Educ.1961, 38, 141.

Stereoisomerism of carbon compoundsNoyce, William K.The purpose of this article is to suggest a different setting for the classification of the various types of stereoisomerism commonly encountered in organic chemistry, with the view to providing a better correlation with contemporary concepts of atomic and molecular structure.Noyce, William K. J. Chem. Educ.1961, 38, 23.

A separation and identification experiment for elementary organic chemistry laboratoryLaughton, Paul M.The student selects a test tube containing two unknowns and is told only that they have been selected from two of three possible groups: a primary or tertiary amine, an aldehyde or ketone, and an acid or phenol. The components are to be separated, their physical properties determined, their categories assigned, and one specific derivative prepared for each.Laughton, Paul M. J. Chem. Educ.1960, 37, 133.

The experimental basis of Kekule's valence theoryHiebert, Erwin N.It is the object of this paper to discuss the experimental basis of Kekule's valence theory of 1858 as seen in the progressive stages of his own experimental career prior to that time.Hiebert, Erwin N. J. Chem. Educ.1959, 36, 320.

Accurate molecular modelsGodfrey, John C.Describes the construction of molecular models that rely on plastics to represents as accurately as possible all of the physical characteristics of real molecules.Godfrey, John C. J. Chem. Educ.1959, 36, 140.

The principle of minimum bending of orbitalsStewart, George H.; Eyring, HenryThe authors present a theory of valency that accounts for a variety of organic and inorganic structures in a clear and easily understood manner.Stewart, George H.; Eyring, Henry J. Chem. Educ.1958, 35, 550.

Isoelectronic molecules: The effect of number of outer-shell electrons on structureGillis, Richard G.The purpose of this discussion is to demonstrate that the concept isoelectric molecules can be of considerable value to the instructor in developing the principles of structural chemistry, to the student in bridging the apparent gap between inorganic and organic chemistry, and the researcher in suggesting analogies that may yield interesting fields for investigation.Gillis, Richard G. J. Chem. Educ.1958, 35, 66.

The numbers and structures of isomers of hexacovalent complexesBailar, John C., Jr.The purpose of this article is to outline a simple method of counting the stereoisomers that can be theoretically formed by monodentate or polydentate ligands and of showing their structures.Bailar, John C., Jr. J. Chem. Educ.1957, 34, 334.

A chart of the stereochemical relationships of the aldosesNelson, Peter F.Provides a chart of the stereochemical relationships of the aldoses that allows students to review and visualize the Rosanoff classification by comparing the D and L enantiomeric forms.Nelson, Peter F. J. Chem. Educ.1957, 34, 179.

Amphoteric molecules, ions and saltsDavidson, DavidIt is the aim of this paper to call attention to the splendid opportunity amphoteric substances afford for the teaching of acid-base principles.Davidson, David J. Chem. Educ.1955, 32, 550.

Molecular Properties / Structure |

Acids / Bases |

pH |

Aqueous Solution Chemistry

A mnemonic for dicarboxylic acidsCox, Gerald J.This short note provides a mnemonic for the names of the dicarboxylic acids.Cox, Gerald J. J. Chem. Educ.1955, 32, 363.

Student experiments on derivatives of 1,2-diphenylethaneFieser, Louis F.Johannes Thiele's classical demonstration of 1,4-addition by reductive acetylation of benzil is used to present a number of interesting theoretical points and an opportunity to separate cis- and trans- isomers through chromatography.Fieser, Louis F. J. Chem. Educ.1954, 31, 291.

Potentialities of protein isomerismAsimov, IsaacThe permutations generated by structural isomerism in proteins could be demonstrated more convincingly and realistically if the amino acid compositions of actual proteins were taken into consideration.Asimov, Isaac J. Chem. Educ.1954, 31, 125.

Differentiating between primary, secondary, and tertiary alcoholsRitter, Frank O.A primary or secondary aliphatic alcohol dissolved in pure glacial acetic acid decolorizes a water solution of KMnO4, while a tertiary alcohol fails to do so; a secondary alcohol will continue to react with KMnO4 solution if a little concentrated sulfuric acid is added, while a primary alcohol does not.Ritter, Frank O. J. Chem. Educ.1953, 30, 395.

The evaluation of molecular formulasGillis, Richard G.Provides two rules for evaluating a molecular formula in terms of the amount of unsaturation present through use of the "equivalent hydrocarbon" concept.Gillis, Richard G. J. Chem. Educ.1953, 30, 126.

Molecular Properties / Structure

The chemical properties of the methyl groupBartlett, Paul D.Summarizes the work that has gone into characterizing the properties and chemical behavior of the simple and ubiquitous methyl group.Bartlett, Paul D. J. Chem. Educ.1953, 30, 22.

LettersBrescia, FrankThe author calls for someone to invent another term for the word resonance as applied to the field of molecular structure.Brescia, Frank J. Chem. Educ.1952, 29, 261.

Resonance Theory |

Nomenclature / Units / Symbols |

Molecular Properties / Structure

Acid-base titration curves: An experiment in acidimetryHendel, James M.The purpose of this activity is to introduce a bit of research into the quantitative analysis course and to illustrate the value of titration curves in deciding what indicator should be used for a particular acid-base titration.Hendel, James M. J. Chem. Educ.1952, 29, 148.

Valence and formulas taught with playing cardsLionetti, FabianDescribes the use of playing cards and a game called "Valence" to help students in organic chemistry understand valence, bonding, and molecular structure.Lionetti, Fabian J. Chem. Educ.1951, 28, 599.

Covalent Bonding |

Molecular Properties / Structure

Osmotic pressure and molecular weightHitchcock, David I.Discusses the use of osmotic pressure to establish the molecular weights of proteins and synthetic polymers.Hitchcock, David I. J. Chem. Educ.1951, 28, 478.

Molecular Properties / Structure |

Chemometrics |

Aqueous Solution Chemistry |

Proteins / Peptides

Teaching amino acid formulationPatton, A. R.Presents a device that aids in explaining the concept of dipolar ions necessary to an understanding of the behavior of amino acids and proteins.Patton, A. R. J. Chem. Educ.1951, 28, 471.

An experiment for the pH meterPecsok, Robert L.These procedures are designed for a Beckman Model H-2 line operated pH meter and include standardization, measurement of pH, titration curve of phosphoric acid, standardization of base, and analysis of mixed phosphate solutions.Pecsok, Robert L. J. Chem. Educ.1951, 28, 252.